ABSTRACT
@# Objective: To investigate the expression of long non-coding RNASNHG16 (lncRNASNHG16) in colorectal cancer (CRC) tissues and cells, and to explore the mechanism of its regulation on the expression of mitochondrial glycerol-3-phosphate acyltransferase (GPAM) via sponging miR-128-3p. Methods: Sixty pairs of colorectal cancerous tissues and para-cancerous tissues that resected from CRC patients, who underwent surgery in the Department of Anorectal Surgery, Gansu Provincial People’s Hospital during Jan. 2014 and Jan. 2017, were collected for this study; In addition, CRC cell lines (SW480, SW620, HCT116, Caco-2,DLD-1, HT29) and colonic epithelial cell line CCD841 were also collected for the study. The expression of SNHG16 in collected tissues and cell lines was determined by Real-time quantitative PCR (qPCR), and its correlation to the clinicopathological features of CRC patients was also analyzed. SW480 cells were transfected with miR-128-3p mimic, miR-128-3p inhibitor, and si-SNHG16, respectively, and then the mRNA expressions of miR-128-3p and SNHG16 were detected by qPCR, the protein expression of GPAM was determined by Western blotting, and the cell proliferation, apoptosis and invasion were detected by CCK-8 assay, colony formation assay, cell apoptosis assay and Transwell chamber assay, respectively. The binding between SNHG16 and miR-128-3p was validated with dual luciferase reporter gene assay and RNA Immunoprecipitation assay. For in vivo experiment, mouse model of SW480 cell exnograft was constructed, and the effect of SNHG16 knockdown on the growth of exnograft was observed. Results: SNHG16 was found to highly expressed in human CRC tissues and cell lines (all P<0.01), and SNHG16 expression level was associated with lymph node metastasis, Duke's stage and patients’survival (all P<0.01). Knockdown of SNHG16 significantly inhibited CRC cell proliferation and invasion, and induced apoptosis (all P<0.01); After SNHG16 knockdown, the volume of exnograft was obviously reduced (P<0.05). Dual luciferase reporter gene assay and RNA Immunoprecipitation assay validated the interaction between miR-128-3p and SNHG16, and they were negatively correlated with each other in CRC patients (P<0.01). The SNHG16 regulated the expression of its down-stream gene GPAM via endogenously sponging miR-128-3p. Conclusion: SNHG16 regulates GPAM expression in CRC cells by sponging miR-128-3p, and SNHG16 and miR-128-3p may serve as potential targets for the diagnosis and treatment of CRC.